The building trades extensively employ portable construction equipment, such as saw horses, sheet metal bending brakes, sheet metal slitters and saw tables. A portable saw table is illustrated, for example, in above-referenced parent application Ser. No. 08/848,977. Portable sheet bending brakes are illustrated in U.S. Pat. No. 4,766,757 and copending application Ser. No. 08/268,808. A portable sheet metal slitter is illustrated in U.S. application Ser. No. 08/310,431. All of such applications are assigned to the assignee hereof.
There is therefore a need in the art for a leg support assembly that is sufficiently versatile to be usable in a variety of applications including saw horses, saw tables, sheet bending brakes and sheet metal slitters, that is light in weight, that is sufficiently strong to support heavy loads, that is readily and rapidly vertically adjustable, that folds to compact size for transportation and storage, that is of inexpensive, corrosion-resistant and light-weight construction, and/or that can be provided in the form of a kit for a variety of different support applications. It is an object of the present invention to provide an adjustable leg support assembly that satisfies one or more of these objectives.
An adjustable leg support assembly in accordance with a presently preferred embodiment of the invention includes a cross brace slidably mounted on a center support and projecting laterally therefrom to opposed ends spaced from the center support. An upper clevis is slidably mounted on the center support above the cross brace. A pair of legs each have one end affixed to the upper clevis, a lower end and a center portion affixed to an associated end of the cross brace. An attachment arrangement is selectively mountable at the upper end of the center support for attachment of structure to be supported. The upper clevis may be adjustably affixed to the center support such that the attachment structure on the center support is adjustably positionable with respect to the lower ends of the legs.
The attachment structure in a preferred embodiment of the invention takes the form of a kit that includes a brace for mounting to the upper end of the center support, a plate selectively mountable to the brace for forming a planar support surface, and a yoke selectively mountable to the brace with sidewalls for embracing a 2.times.4 or other similar wood section of standard dimension. With the planar support affixed to the brace, structures such as a portable sheet bending brake, a portable sheet metal slitter or a portable saw table may be affixed to and supported by the adjustable leg support assembly. With the yoke mounted to the brace, the adjustable leg support assembly may be used in pairs to form a saw horse for supporting structures of any desired character. Alternatively, the attachment structure may be provided in the form of integral and selectively removable elements.
The center support in the preferred embodiments of the invention comprises a length of metallic tube stock, preferably of square cross section. A plurality of through-openings are spaced from each other lengthwise of the center support, and cooperate with a through-opening in the upper clevis for selectively positioning the upper clevis on the center support, preferably by means of a pin that is selectively removable from the upper clevis and center support. The pin in the preferred embodiment of the invention is pivotally mounted on a U-shaped brace having a yoke at the free end of the base for selectively capturing the free end of the pin, and thereby firmly locking the pin in position on the center support and upper clevis. Feet are pivotally mounted at the lower ends of the legs, and include teeth for digging into soil and thereby firmly anchoring the adjustable leg support assembly in position.
The adjustable leg support assembly in accordance with the preferred embodiments of the invention is constructed of strong light-weight anodized aluminum alloy for corrosion resistance and long life. The leg assembly supports heavy loads, up to two thousand pounds. Height adjustments may be readily implemented, over a range of 28 inches to 37 inches in the preferred embodiments of the invention. The leg assembly folds to compact size, preferably a 5 inch by 33 inch size, for convenient handling and storage. The feet of the invention provide support on uneven terrain. Furthermore, the adjustable leg support assembly in accordance with the invention is of inexpensive construction, and the attachment elements may be readily provided in the form of a kit for a variety of support applications.